A Blessing in Disguise

塞翁失马 A Blessing in Disguise
In China there's a saying: 塞翁失马，安知非福？(Sàiwēng shī mǎ，ānzhī fēifú?) It could be translated something like: Just like the old frontiersman losing his horse, who knows but that this may be a blessing in disguise.
Anyway this story is a simply told version of the folk tale which gives us this 成语.